B6 - Biofuels
- Created by: Naomi
- Created on: 21-01-13 13:01
View mindmap
- Biofuels
- Green plants use light energy from the sun to photosynthesise
- Photosynthesis produces energy and plants use the energy to grow and gain mass
- The mass of plants is called biomass. The energy that is trapped in biomass can be used to make biofuels
- Photosynthesis produces energy and plants use the energy to grow and gain mass
- Biogas
- Biogas is a fuel that contains
- Mainly methane
- Some carbon dioxide
- Very samll amounts of hydrogen, nitrogen and hydrogen sulphide
- Biogas can be made on a large scale in a digester
- This uses a continuous flow method as organic wastes are constantly added and the gas and remaining solids are constantly removed
- The biogas that is made is:
- Burnt to generate electricity
- Burnt to produce hot water and steam for heating systems
- Used as fuel for vehicles
- Biogas production is affected by temperature because as the temperature increases, the bacteria multiply faster and the enzymes within them work better
- Above 45 degrees, the enzymes are denatured and the bacteria die
- Biogas is a fuel that contains
- Ways to make biofuels
- Fast growing trees are grown and the wood is burnt
- Biomass such as sugar or waste material is fermented using bacteria or yeast and the product is used as fuel
- Alcohol is made by fermtation and is mixed with petrol to make gasohol
- This is used to make petrol
- Gasohol is an ideal fuel where there is ample sugar cane but little oil
- Alcohol is made by fermtation and is mixed with petrol to make gasohol
- Gasohol
- Alcohol is made by fermtation and is mixed with petrol to make gasohol
- This is used to make petrol
- Gasohol is an ideal fuel where there is ample sugar cane but little oil
- Alcohol is made by fermtation and is mixed with petrol to make gasohol
- Advantages and disadvantages of biofuels
- Advantages
- Much cleaner fuel than fossil fuels
- Using biofuels means that fossil fuels will last longer
- Biofules do not increase the net levels of carbon dioxide in the air
- Called carbon-neutral if they are burnt at the same rate as the biomass is being produced
- They do not release particulates when they are burnt
- Disadvantages
- It destroys large ares of natural habitat to grow the biomass
- It contains less energy than other fossil fuels
- Advantages
- Green plants use light energy from the sun to photosynthesise
Similar Biology resources:
Teacher recommended
Comments
No comments have yet been made